Apparatus and method for making shower curbs

ABSTRACT

A shower curb is built by stacking two or three horizontally disposed 2″×4″ boards in a vertical stack and covering them with a shower liner. A three-sided frame having upstanding parallel front and back walls that depend from and are perpendicular to a top wall is placed over the liner and the boards. The frame is lattice-like and has a large plurality of openings formed in it. A cementitious material is applied to the frame so that the material enters into the openings and is screeded until it completely covers the boards and is flush with the frame. Ceramic tiles are then laid in overlying relation to the resulting structure. In a second embodiment, the top wall of the frame is pitched toward the shower to provide drainage.

BACKGROUND OF INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates, generally to the art of construction. More particularly, it relates to methods and devices for making shower curbs.

[0003] 2. Description of the Prior Art

[0004] A shower curb, also known as a shower entrance threshold, functions to retain water within the shower. It takes the form of a short wall that divides the shower floor from the floor of the room adjacent the shower. Typically, the wall is only a few inches in height so that a person entering or exiting a shower can easily step over the wall. Since the wall is about the height of a roadway curb, such short shower walls are known as shower curbs.

[0005] Builders have developed a number of devices and methods for constructing shower curbs.

[0006] Perhaps the most obvious but least desireable technique is to build a form of the desired size and to pour concrete into the form. The concrete is allowed to cure and is then covered by tile. However, a work crew must make two trips to the construction site to make such a curb. The first trip is needed to build the form and pour the concrete, and the second trip is needed after the concrete has cured to remove the form and lay the tile.

[0007] The first trip can be eliminated if a pre-cast concrete curb is delivered to the site, ready to be covered with tile. However, pre-cast curbs are heavy, expensive, and not easily cut-to-length.

[0008] A pre-fabricated, lighter in weight curb can also be provided if lighter materials are substituted for the concrete. However, all of the known substitute materials, such as foamed plastic, lack durability and as such are unacceptable substitutes.

[0009] Styrene can be used in shower curb construction, but it is expensive and requires the use of wire mesh to support the mud that overlies the styrene.

[0010] When a shower floor is made of fiberglass reinforced plastic material, the shower curb may be made of the same material as an integral part of the construction. However, such materials are not easy to work with and specialized skills are required.

[0011] A technique that has grown in favor overcomes many of the drawbacks associated with the prior art techniques. Three 2″×4″ boards, commonly known as “two by fours,” are cut to the desired length and laid horizontally in a vertical stack. The boards are then covered by a flexible shower liner. Specifically, the shower liner extends from the shower floor, up the inside (shower-side) of the boards, across the top of the boards, and down the outside thereof. Although shower liners are made of several different materials, the most common material is vinyl.

[0012] A first flat cement backing board is then placed into overlying relation to the inside surface defined by the boards, in overlying relation to the liner, and nailed into place. This nailing punctures the shower liner. Moisture therefore seeps through the liner and with the passage of time, eventually accumulates below the shower pan in sufficient quantity to cause mildew build-up in the shower area. Moreover, the moisture causes the boards to swell and rot, eventually destroying the integrity of the tiles.

[0013] Second and third cement backing boards are then placed into overlying relation to the top and outside surfaces of the two by fours, respectively, and nailed into place.

[0014] A cementitious material, commonly known as “mud,” is then applied to each cement backing board. Ceramic tile is then applied to the mud.

[0015] Using light-in-weight, easily cut-to-length two by fours as the primary building blocks of the shower curb eliminates the problems associated with custom-built concrete curbs, pre-cast concrete curbs, and curbs formed of less durable and harder-to-install materials.

[0016] However, it is time-consuming to attach the cement backing boards to the two by fours, and the puncturing of the liner when the nails are used is problematic. It is possible to seal the punctures with suitable waterproofing materials, but most installers skip the waterproofing step. It may take a few years for the mildew and swelling/rot problem associated therewith to appear, and the homeowner is seldom aware of the source of the problem.

[0017] Moreover, laying tile on the vertical cement backing boards is problematic.

[0018] What is needed, then, is an apparatus and method that incorporates the advantages derived from the use of two by fours as the basic building blocks of a shower curb, but which is not subject to the disadvantages associated therewith. Specifically, the new apparatus and method should not result in nail-puncturing of the shower liner and should facilitate the laying of tile on the mud.

[0019] However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.

SUMMARY OF INVENTION

[0020] The long-standing but heretofore unfulfilled need for an improved apparatus and method for building shower curbs is now met by a new, useful, and nonobvious invention. The novel apparatus for building a shower curb includes a plurality of horizontally disposed boards stacked in a vertical array. The boards are cut to a common length equal to an elongate space within which is to be built the shower curb. A flexible shower liner is disposed in overlying relation to the plurality of boards and a three-sided frame is disposed in overlying relation to the boards and in overlying relation to the flexible shower liner.

[0021] The three-sided frame includes a top wall, a front wall, and a back wall. The front wall and the back wall are disposed in parallel relation to one another and in perpendicular, depending relation to the top wall. A plurality of openings is formed in the top wall, front wall, and back wall and said plurality of openings is adapted to receive a cementitious material. The three-sided frame has a predetermined depth that determines the depth of the cementitious material when said cementitious material is applied to the frame.

[0022] The boards and liner are adapted to be completely covered by the cementitious material when the cementitious material is applied to the boards and liner through the plurality of openings. The depth of the cementitious material is substantially equal to the predetermined depth of the frame so that the top wall, front wall, and back wall of the frame are substantially flush with the cementitious material.

[0023] Tile is laid atop the cementitious material to complete the shower curb.

[0024] The novel frame is made of a preselected material that is adapted to be cut to length as needed for a particular application. In a preferred embodiment, plastic is the preferred material from which the frame is made.

[0025] A first interlocking means is formed in a preselected part of the frame at a first end of the frame and a second interlocking means is formed in the preselected part of the frame at a second end of the frame. The first and second interlocking means are of complemental construction so that two linearly aligned frames are interlockable with one another. The preselected part is preferably the front wall of the frame.

[0026] An important object of this invention is to lower the level of skill required to make a shower curb by eliminating the need for a skilled craftsman to design and sculpt a unique shower curb for each shower curb installation.

[0027] A very closely related object is to provide a new shower curb construction technique that results in shower curbs of consistently high quality.

[0028] Another object is to provide an apparatus and method that eliminates the use of cement backing boards, styrene, wire mesh, and other materials that are expensive or difficult to work with, or both.

[0029] Still another object is to provide an apparatus and method for building a shower curb that eliminates nail-puncturing of shower liners and the swelling and rotting of boards that follows.

[0030] Yet another object is to facilitate the laying of tile when making a shower curb.

[0031] These and other important objects, advantages, and features of the invention will become clear as this description proceeds.

[0032] The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0033] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:

[0034]FIG. 1 is a perspective view of three boards in a vertical stack that have been cut-to-length to fit a space within which a shower curb is to be built;

[0035]FIG. 2 is depicts the boards in end view after a plastic shower liner has been positioned in overlying relation to the boards;

[0036]FIG. 3 is an end elevational view depicting the plastic frame member in overlying relation to the liner-covered boards before mud is applied thereto;

[0037]FIG. 4 is a front elevational view of a novel plastic frame member;

[0038]FIG. 5 is an end elevational view depicting the structure of FIG. 3 after mud has been applied thereto;

[0039]FIG. 6 is an end elevational view depicting the structure of FIG. 3 after ceramic tile has been laid in overlying relation to the mud; and

[0040]FIG. 7 is an end elevational view of a second embodiment of the novel frame.

DETAILED DESCRIPTION

[0041] Referring now to FIG. 1, it will there be seen that the reference numeral 10 denotes a perspective view of the boards that form the foundation for the present invention.

[0042] More particularly, three 2″×4″ boards, collectively denoted 12, and hereinafter referred to as two by fours, are cut-to-length so that they fit into the space provided for a shower curb and are vertically stacked as depicted. The number of two by fours is not critical, and can be reduced or increased. In most cases, two or three boards are used.

[0043] Shower liner 14 (FIG. 2) is positioned below a sloped shower pan, not shown. When shower liner 14 is installed, a sufficient quantity thereof is left over and extends beyond the outer edge of the pan for the purpose of overlying the two-by-fours that will form the base of the shower curb.

[0044] The vertical, shower-side extent of shower liner 14, denoted 14 a in FIG. 2, is punctured by nails when a cement backing board of the prior art, not shown, is nailed to the inside wall (the right wall as depicted)) collectively formed by the stacked two by fours.

[0045] No cement backing boards are required when making a shower curb with the novel apparatus.

[0046] After flexible shower liner 14 has been folded so that it overlies the inside, top, and outside walls formed by the two by fours, as depicted in FIG. 2, novel frame 16 is positioned in overlying relation to said shower liner 14 as depicted in FIG. 3. It should be understood that the relative thickness of shower liner 14, which is typically formed of a vinyl plastic as aforesaid, is greatly exaggerated in the drawings just to make the liner more visible.

[0047] As perhaps best understood by comparing FIGS. 3 and 4, frame 16 is a three-sided structure including a top wall 18, front wall 20, and back wall 22 that has a lesser extent than front wall 20. Back wall 22 has less height because its lowermost edge 24 abuts the sloped shower pan at its maximum elevation whereas lowermost edge 26 of front wall 20 abuts the level floor of the room adjacent the shower.

[0048] In a preferred embodiment, top wall 18, front wall 20, and back wall 22 are molded or otherwise manufactured separately and are snap-fit or otherwise secured together to form frame 16. An integrally formed frame is also within the scope of this invention.

[0049] Front wall 20 and back wall 22 are parallel to one another and both are perpendicularly disposed relative to top wall 18. The respective lowermost edges of front wall 20 and back wall 22 may be rounded to facilitate placement of frame 16 into overlying relation to the plastic-covered base formed of the three two by fours.

[0050] Although each wall 18, 20, and 22 is depicted as having a plurality of square or rectangular openings, collectively denoted 30 in FIG. 4, it should be understood that the shape of the openings could be of any predetermined geometric configuration, including circular, triangular, and the like.

[0051] It is important to note the depth of said three walls. In this embodiment, each wall has a depth of about half an inch, although that particular depth is not absolutely critical. The depth must be adequate to receive and retain a sufficient amount of cementitious material, also known as mud.

[0052] As depicted in FIG. 5, mud 32 is applied and screeded so that it fills each opening 30, i.e., until it fills the interstitial spaces of frame 16. Frame 16 prevents the mud from sliding down the vertical face of front wall 20 and back wall 22, thereby facilitating the tile-laying procedure.

[0053] As indicated in FIG. 6, tiles 34 are then laid atop mud 32 in a well-known way to complete the shower curb installation.

[0054] In the second embodiment of FIG. 7, a pitch toward the shower is provided in top wall 18 a of frame 16 so that water atop said top wall is directed toward the shower drain. The illustrated pitch is greatly exaggerated to better convey the idea.

[0055] Frame 16 eliminates the need for cement backing boards, thereby greatly simplifying the curb-building job. The elimination of cement backing boards further eliminates the nailing of said cement backing boards to the two by fours, thereby eliminating the puncturing of the shower liner.

[0056] Each frame 16 is adapted to be interlocked in end-to-end relation with another frame 16. Note in FIG. 4 that dove-tailed grooves 16 a are formed in the frame at a first end thereof and that complementally formed dove-tailed projections 16 b are formed at a second end thereof. In this way, it is a simple matter to interlock together two frames 16 by slideably inserting the projecting dove-tails 16 b of a first frame into the recessed dove-tails 16 a of a second linearly aligned second frame. Any other suitable interlocking means is within the scope of this invention, it being understood that interlocking dove-tails are merely one type of suitable interlocking means.

[0057] Similarly, if an application includes a linear space that has less extent than a single frame 16. or less extent than two interlocked frames, it is easy to cut a frame 16 to size as needed.

[0058] Frame 16, being made of plastic, is light-in-weight and easily cut-to-length. It is inexpensive as well and its use significantly shortens the time and reduces the effort required to build a shower curb of high quality. Its use also lowers the skill level required of the installer. Accordingly, even inexperienced workers can consistently build high quality curbs when using the novel apparatus and following the steps of the novel method.

[0059] It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0060] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.

[0061] Now that the invention has been described, 

1. An apparatus for building a shower curb, comprising: a plurality of horizontally disposed boards stacked in a vertical array, said boards being cut to a common length equal to an elongate space within which is to be built said shower curb; a flexible shower liner disposed in overlying relation to said plurality of boards; a three-sided frame disposed in overlying relation to said boards and in overlying relation to said flexible shower liner; said three-sided frame including a top wall, a front wall, and a back wall; said front wall and said back wall being disposed in parallel relation to one another and in perpendicular, depending relation to said top wall; said three-sided frame having a predetermined depth; a plurality of openings formed in said top wall, said front wall, and said back wall; said plurality of openings adapted to receive a cementitious material; said boards and liner adapted to be completely covered by said cementitious material when said cementitious material is applied to said boards and liner through said plurality of openings at a depth substantially equal to said predetermined depth of said frame so that said top wall, front wall, and back wall of said frame are substantially flush with said cementitious material; whereby tile is laid atop said cementitious material to complete said shower curb.
 2. The apparatus of claim 1, wherein said frame is made of a preselected material that is adapted to be cut to length as needed for a particular application.
 3. The apparatus of claim 2, wherein said preselected material is plastic.
 4. The apparatus of claim 2, further comprising a first interlocking means formed in a preselected part of said frame at a first end of said frame and a second interlocking means formed in a preselected part of said frame at a second end of said frame, said first and second interlocking means being of complemental construction so that two linearly aligned frames are interlockable with one another.
 5. The apparatus of claim 4, wherein said preselected part is said front wall of said frame.
 6. The apparatus of claim 1, wherein said top wall is horizontally disposed.
 7. The apparatus of claim 1, wherein said top wall is pitched so that water does not collect atop it. 